Brake testing mechanism



P 1935' c. E. STARR BRAKE TESTING MECHANISM Filed May 23, 1928 2Sheets-Sheet 1 av Wei 4 /V 7'02 (SHAW/2,221,854". swam: m

April 7, 1936. r c. E. STARR BRAKE TESTING MECHANISM Filed May 23, 19282 Sheets-Sheet 2 Patented. Apr. 7,

PATENT OFFICE m rasrmcimcnamsu lharles E. Starr, Whittier, Calilh,assignorto. 'Bendix Aviation Corporation, South Bend, but,

a corporation of Delaware Application May 23, 1928', Serial No. 279,905

ing machine is shown having a movable body adapted to support a vehiclewheel. Means are provided for rotating the wheel against the resistanceof the brake while being supported by the movable body so that themovement of the "supporting body is a fimction solely of the weightthereon and the force necessary to turn the wheel against the resistanceof the plate. Means are provided for evaluating the movement of thesupporting body to indicate the condition of the brakes and the amountof adjustment necessary to equalize their effect. The present inventionis designed to more equally indicate and evaluate braking efiectsuponthe wheels of a vehicle, equally compensate for unequal distribution of'weight and simulate actual driving conditions;

Accordingly, as in my prior application; the weight of.the vehicle issupported on a plurality of movable bodies to obtain a truer evaluationof the effect of the brakes, the supporting bodies being particularlyconstructed to give an accurate compensation. It is a primary object ofmy invention to provide an apparatus which will readily and accuratelyindicate the true condition of the brakes and their braking effect upontheir associated wheels under substantially road conditions.

' Another object of my invention is the provision of an' apparatus ofthe character described which will indicate the degree of brakeadjustment required in order to give equal braking effect upon aplurality of wheels while compensating for the unequal distribution ofweight on the wheels to be tested if necessary.

Another objectof my invention is the provision of means adjacent thetesting apparatus for retaining a wheel thereon while being tested.

Another object of my-invention is the provision,

in an apparatus of the character described, of

. means for providing 'a plurality of frictional con- A fiu'therobjectof my'invention is the pro-'- vision of an apparatus of the characterdescribed 1 19 Claims. (01.265-25) for simultaneously testing the brakesof all four wheels of a vehicle such as an automobile.

My invention possesses other objects and valuable features, some ofwhich will be set forth in the following description of my invention..It is 5 to be understood that I do not limit myself to the showing madeby the said description, as I may adopt varying forms of my inventionwithin the scope of .the claims.

Fig. 1 is aside elevation showing the testing machine and the front andrear wheels of a vehicle supported thereon. The position of the 'movablecarriage for supporting the front wheels of a, vehicle is shown in itsinitial position by dotted lines, and a portion isomitted to shorten 5the length of the figure.

Fig. 2 is a plan view of the apparatus illustrated in Fig. 1.

In greater detail as shown in the illustrated embodiment, my inventioncomprises a fixed plat- .form I mounted on suitable supports such asI-beams 3. The platform serves as a base for the testing machine for oneset of wheels of a vehicle such as an automobile. Broadly the testingmechanism comprises two sets of rollers the sets being spaced apartapproximately a distance equal to the tread of a vehicle. Each setcomprises a pair of spaced rollers arranged with their axes parallel toeach other and to the axles of the wheels. The rollers constituteSupports for one pair of wheels such as the rear wheel A of a vehicle. Apair of inclined runways 4 are provided one for each pair of rollersextending from 'the rollers downwardly to the floor upon which 'In suchan apparatus means are provided for accommodating the testing device tovehicles of various wheel-base lengths. For this purpose a pair of railsare attached to the front end of platform 2 and extend forwardly fromeach side thereof. A movable carriage 6 mounted on wheels 1 is adaptedto travel on rails 8. Fixed to the carriage is a testing machine for thesecond set or front wheels of a vehicle, the testing machine beingsimilar to the mechanism on the station ary platform comprising twopairs of rollers the l rollers of the second set being in alignment withthe respeotive rollers on piatform 2. The movable carriage is providedwith standards 9 extending upwardly from the rear end thereof forsupporting runways I l in position to extend rearwardly in substantiallyhorizontai position and arranged to pass over and rest on each set ofrollers mountedon the fixed platform when the carriage is movedintoposition adjacent the fixed platform as would be the case when thevehicle is first driven on to the testing device.

It is thus apparent when an automobile is driven over the runways llresting on the rollers carried by the fixed platform that upon continuedmovement thereof, the front wheels B will ride up runways 4 over runwaysII and onto the rollers carried by the movable carriage, and restinposition between them. Upon further movement of the vehicle, thecarriage will travel forward upon rails 8 until the rear wheels restbetween the rear rollers carried by platform 2, and the vehicle is thenstopped. with the vehicles in place the movable carriage may be fixed tothe rails by means of any suitable mechanism such as the clamp l2. Inmoving the vehicle off the apparatus, a reversal of the above operationtakes place.

. pivotally secured to plates 2| at their lower ends.

Arms 2| are held in spaced position by means of a shaft or red 23 andspacer tube or ferrule 25 the rod passing through theupper ends of arms20 and extending laterally beyond the outer side thereof for reasonswhich will hereafter appear. Stops 22 are provided on the bearing platefor limiting movement of the arms in one direction. Pivotally carriedupon the shaft adjacent each arm are two V-shaped supports 26 betweenwhich at the ends thereof are journalled rollers 21 and 28 forengagement with the vehicle wheel. Shaft 29, upon which roller 23 iskeyed, projects beyond the supports to form pins engaged by elongatedslots 30 in the upper ends of controi links 3|, which links arepivotally secured'at their lower ends for rocking movement to hearingplate '2 I,

It is preferred to position guide means for maintaining the vehiclewheel on the rollers. Therefore, on the inner support 26 there isjournaled a roller 32 to rotate about a vertical axis; so as to f rotateupon motion of the wheel and which coc-pcrates with a similar rolleruponthe other pair of wheel rollers 21 and 26 to prevent lateral movement ofthe vehicle upon the rollers and 23.

Means are provided for driving the rollers 21 and 28 in rotationtogether comprising a flexible shaft 33 connected to roller 2! throughuniversal joints 34, as illustrated in Fig. 2, driven by means of amotor 36 mounted on the carriage and through drive shaft 31. The driveshaft is adapted to turn the flexible shaft through any conventionalgear reduction system 38 interposed between the shafts. Roller 26 isdriven from roller 21 by means of sprockets 39 keyed to the respectiveroller shafts and a sprocket chain 4| connecting the sprockets.Preferably the gear reduction system 38 is such that theiwh'eels of theve- .hicle are turned at about 8 to 10 R. P. M. The

direction of rotation of the rollers, as indicated Means are providedfor'yieldingly resisting.

bodily movement of the-supports 26, the rollers mounted thereon and thelinks 20 in a' direction 1 opposite to that-in which movement is lhnitedby stops 22 and control links 3f. Journaled on the shaft 23 whichextends beyond the arms 20 is a piston 42 adapted to slide within theoil filled cylinder 43 pivotally mounted on the carriage. Connected tothe cylinder a pressure gauge 44 for indicating the pressure developedupon compression of the oil in the cylinder.

Preferably the gauge'is provided with a pair of pointers 46 and 41, oneof which is a free pointer or maximum indicating pointer adapted to movewith the other dial and remain at the highest pressure indicated. a 1

0pe1'ation.When a vehicle such as an automobile is mounted on therollers, the motors for each set of wheels are started to turn therollers of the supports in a direction indicated by the arrows ofFig. 1. As long as the wheel brakes are not applied, the wheels A and Bwill rotate with the rollers. Upon application of the brakes, resistanceto the rotation of the wheels is offered,

and the resultantforce will cause a movement of the supports andassociated rollers 21 and 2B in a direction opposite to that of therotation of the rollers thereby effecting a. lifting of the vehiclewhich is supported entirely by'the bodily movable rollers. will causepiston 42 to compress oil in the cylin- Bodily movement of the supportsders and the readings can then be taken from the gauges. The differencesof the gauge readings will indicate the unequality of braking effectupon the four brakes, and the brake adjustment required to equalize thebrakes, consequently the brakes can be adjusted accordingly.

In making the test, it is preferred to. equally inflate the tires of thevehicle wheels if they are pneumatic, order to offer the same frictionalresistance for all the rollers.

During the testing operation, the vehicle tends to move off of theapparatus in a direction in which the rollers turn. It is, therefore,preferred to provide means for holding the vehicle from movement duringthe test. For this purpose a'shaft 46 is iournaled in suitable bearingsupports 49 on the front of the movable carriage. Secured to the shaftand adapted to be wound around it, may be a chain 5| having'a'hoek 52which is attached to the front axle C of the wheel before the test ismade. The shaft then may be turned by means of handle 53 to tighten thechain which isrheld taut by means of a suitable pawl andratchetarrangement 5 1. After the test, the chain is released and thevehicle may be driven off the apparatus.

From the above description, it is apparent that having two drivingrollers, mounted on the support which is pivotally mounted for rockingmotion, resultsnot only in an increased frictional contact with thewheel giving more positive drive, but also eliminates the size of thewheel as a factor in the indication given. This makes the indication afunction of the weight supported by the rollers and the braking effortas the only variables.

a,ose,ess

Iclaim: a

1. A machine for testing the effect of a brake on a wheel comprising arockable arm, means for limiting movement thereof in one direction,

. means for yieldingly resisting movement thereof in an oppositedirection, a support pivoted to the arm, a plurality of rollersjournaled on said support and adapted for engagement with a brakedwheel, and means for driving one of said rollers.

2. A-machine for testing the effect of a brake on a wheel comprising arockable arm, means for limiting movement thereof in one direction,means for yieldingly resisting movement thereof in an oppositedirection, a support pivoted to force of said movement, a supportpivoted intermediate its length to said arm, a roller journaled on eachend of said support and adapted for engagement with a braked wheel, andmeans for driving one of said rollers.

- 4. A machine for testing the effect of a brake on a wheel comprising apivoted arm, means for limiting movement ofjhe arm in one direction,

means for yieldingly resisting movement thereof in an oppositedirection, a support mounted on said arm, a plurality of rollersiournaled on said support and adapted for engagement with a brakedwheel, and means for driving one of said rollers.

5. A machine for testing the effect of a brake ou a wheel comprising apivoted arm, means for limiting movement of the arm in one direction,means for yieldingly resisting movementthereof in an opposite direction,a support movably mounted on said arm, means for limiting movement ofsaid support, a plurality of rollers journaled on the support andadapted for engagement with a braked wheel, and means for drivingoneofsaid'rollers.

6. A-machine for testing the effect of a brake on a wheel comprising apivoted arm, means for limitingmovement of the arm in one 'direction,means for .yieldingly resisting movement thereof in an oppositedirection, a support pivotally mounted on said arm, a control link forsaid support, a plurality of rollers journaled on the support andadapted for engagement with a braked wheel, and means for'driving one ofsaid rollers. 1

7. A machine for testing the effect of a brake on a wheel comprising apivoted arm, means forlimiting movement of the arm in one direction,means for yieldingly resisting movement thereof in an oppositedirection, a support 'pivotally mounted on said arm and having a pinthereon,

' a control link for said support and having a slot 8. A machine fortesting the effect of a bra :e'

on a wheel comprising a movably mounted arin, means for limitingmovement of the arm in one direction, means for yieldingly resistingmove-- ment thereof in an opposite direction, a support mounted on saidarm, a plurality of rollers jourengagement with a braked wheel, andmeans fordriving said rollers.

9. A machine for-testing the eifect of the brake on a wheel comprising arockable support adapted to be placed under the wheel to be tested and 5mounted for bodily movement relatively to the wheel being tested when insupporting position,

a plurality, of rollers journalled for rotation on said support andadapted for frictional engagement with a brake wheel ind means fordriving one of said rollers to rotate the wheel thereon. 10. A machinefor testing'the effect of the brake on a wheelcomprising a rockablesupport adapted to be placed under the wheel to be'tested and mountedforbodily movement relatively to the wheel being tested when insupporting position, a plurality of rollers journalled for rotation onsaid support and adapted for frictional engagement with a.' brake wheel,means for driving one of said rollers to rotate the wheel thereon andmeans to evaluate the bodilymovement of said support. v

11. In a machine for testing the effect of a brake on a wheel, a pair ofspaced rollers for supporting the wheel, means for supporting said 26thereby and means for evaluating the bodily 80 movement caused by suchrotation.

12'. A machine for testing the effect of a brake on a wheel comprising abase, a plurality of movable member's upon which the wheel rests, a

roekable member supporting the movable members, said rockable memberbeing attachedto said base for bodily movement relative thereto, meansfor resisting bodily movementsthereof and means for rotating the wheelagainst reslstance to rotation while on said members,

whereby movements of said members are a function of the weight. ofthewheel thereon and of the force for rotating. the wheel againstresistance.

13. A machine for testing the effect of a brake on a wheel comprising abase, a plurality of movable members upon which the wheel rests, arockable member supporting the movable members, said rockable memberbeing secured to said base for bodily movement relative thereto, meansfor resisting bodily movements thereof and means for rotating the wheelagainst resistance to rotation while on said movable members wh'reby/movements of said members are a function of we weight of the wheelthereon and of the force for rotating the wheel against resistance andindicaiors for evaluating the movement of said memers. v

14. A machine for testing the effect of a brake on-a wheel comprising abase, a plurality of rollers, a rockable member supporting the rollers,.a member pivotally connected to said rockable member .and to said base,said rollers being mounted for rotative movement about their axes andfor bodily movement, means for resisting 5 bodily movements thereof andmeans for rotat-" ing one of said rollers to rotate the wheels supportedthereon against resistance to rotation whereby the bodily movementofsaid rollers-is' a'function of the weight of the-wheel thereon whensaid wheel is rotated against resistance.

15. A machine for testing the effect of abrake on a wheel comprising abase, aerockable support attached. thereto for bodily movementrelatively to said base, means; for resisting bodily movements of saidsupport, a phirality of.rollers Journailed on said support and uponwhich the wheel rests, and means for driving one 01' said rollers torotate said wheel against resistance to rotation whereby movements ofsaid support are a function of the weight of the wheel on said supportand the force for rotating the wheel against resistance while on saidsupport.

16. A machine for testing the eflect of a brake on a wheel comprising abase, a rockable support attached thereto for bodily movement relativelyto said base, means for resisting bodily movements of said support, aplurality of rollers: journalled on said support and upon which thewheel rests, and means fordriving one of said rollers to rotate saidwheel against resistance to rotation whereby movements of said supportare a function of theweight of the wheel on said support, and the forcefor rotating the wheel against resistance while on said support andmeans .for evaluating the bodily movement'ot said rollers while saidwheel is being rotated on said support.

17. In a machine for testing the efiect of a" brake on a wheelcomprising a base, a rockable support attached to said base for bodilymovements relatively thereto, means for resisting bodily movementsthereof, a plurality of rollers journalled on said'supDOrt and uponwhich the wheel rests; and means fordriving one of said rollers torotate saidwheel while on said support whereby movements of said supportare a function of the weight of the wheel on said support and the forcefor rotating the wheel for resistance while on said support.

18. A vehicle brake tester, comprising a plurality of supporting bodieseach designed to carry a wheel of a vehicle, pivotally mountedoscillatable elements supporting said bodies to move the same in anarcuate path from a normal low point of the arc, anindicator for each ofsaid bodies, and a plurality of means actuated by movement of saidbodies for operating said indicators.

19. In a brake testing machine, a support for a vehicle wheel, andmeans, for movably mounting said support such as to cause an upwardmovement of the same against the weight of the vehicle due to brakeresistance when a force is applied to the wheel tending to rotate thesame.

CHARLES E. STARR.

